Wheel hardening apparatus



y 1941- F. s. DENNEEN 2,240,493

' WHEEL HARDENING APPARATUS Filed Dec. 31, 1937 Patented May 6, 1941 2,240,493 WHEEL HARDBNING APPARATUS Francis S. Denneen, Cleveland, Ohio, assignor to The Ohio Crankshaft Company, Ohio, a corporation of Ohio Cleveland,

Application December 31, 1937, Serial No. 182,922

4 Claims.

This invention relates to apparatus for hardening the outer peripheral rim of circularferrous articles and is more particularly directed to hardening car wheels of various sizes and shapes. The invention may be employed either with cast or mechanically formed wheels. A

The chief object of my invention has been to provide an improved apparatus for hardening the rims of car wheels and the like in a minimum period of time and in such manner as results in an improved product. The. apparatus accomplishe the necessary heating by reason of the resistance of the wheel to passage of electric current and may be employed with single or double flanged wheels or with wheels which are unflanged.

Other objects of my invention will become apparent from the following specification and from the accompanying drawing. The novel features are summarized in the claims.

In said annexed drawing:

Figv 1 is a. vertical section through the preferred form of apparatus used;

Fig. 2 is a schematic view showing the heating apparatus of Fig. 1 in an alternative position;

Figs. 3. and 4 illustrate the use of brush contactors to apply current to the wheel.

The portion of the wheel against which the contactors bear should be cleaned or machined to provide a clean and smooth contact surface 1 or engagement with the conductors and the contact is improved by plating the region contacted with chromium or other suitable metal. wheel to be heated and hardened with my apparatus may be pre-heated by conventional methods above the critical temperature and allowed to cool to approximately 1200 F., when it is ready to be differentially hardened.

Referring to Fig. 1, my apparatus comprises a c fra me Ill mounted on a suitable base. A wheel supporting shaft IS with a wheel engaging shoulder i6 is slidably carried in the frame and surrounded by a sleeve l8 reciprocable with the shaft as desired. Reciprocation of the sleeve and shaft is effected by the yokes25 and 22 riding in annular recesses 24 and 25 of the sleeve and shaft respectively. The yokes are shifted by mechanism connected to links 25 and 28 and not further shown. The frame presents a slideway 29 on which the sleeve slides.

A pair of conductingrings, one bearing on each side of the wheel, are employed to supply heating current thereto. One ring is carried by the sleeve and comprises a hollow conducting member 30, the top of which is shaped to closely conform to the wheel contour and establish intimate electrical contact therewith. The ring 30 is cooled by piping 33 passing into the sleeve l8 and discharging to an annular recess 35 therein. The recess communicates with an opening in the The shaft- I5 which in turn is connected to a vertical pipe 31 passing to the bottom of the shaft and connected by a universal coupling 38 to a suitable source of coolant under pressure.

A wheel web cooling ring 40 may be provided when desired to control the web temperatureand may be supported by piping 33. It is supplied with coolant through the connection 38 and discharges against the web of the wheel through a plurality of spray orifices to maintain the web in substantially unheated condition.

The second conducting ring to supply current to the wheel is indicated at 45 and comprises a rotatable hollow member resiliently and insulatably supported on a framework 41 and spaced from the top of the frame by a relatively heaVy spring bearing at one end against the ring spider and at the other against a thrust bearing 52. The ring 45 is supplied with coolant by means of a. suitable inlet, not shown. H

Current is supplied to the rings 30 and 45 by brushes 55 resiliently carried by. the frame Ill and connected to a suitable source of current 50;

In operation a wheel is mounted on the shoulder l5 of the shaft while the sleeve I8 is maintained in its lowermost position. The wheel is moved into position and supported until picked up by the shoulder. The sleeve l8 and ring 30 are then moved upwardly by force exerted through the link 25 into contact with the wheel. The links 25 and 28 then act together to raise the sleeve and shaft upwardly until the wheel contacts the upper ring 45 and compresses the spring 50$.insuring good contact between the wheel and ring. The leads to the generator are then closed and current passed through the brushes 55 and rings 30 and 45 to the wheel. Theinherent electrical resistance of the wheel heats the portion indicated by the shaded line in Fig. l to the desired hardening temperature, after which the wheel is quenched.

The quenching means comprises a quench tank 55 surrounded by a pair of quench rings 61, each of which discharges to a plurality of orifices 10. The quench tank is normally provided with enough coolant to cover the wheel when the heated portion is adjacent the orifices. Coolant is forced through the orifices at a pressure sufficient to forcibly project against the heated portion of the wheel and remove all gas bubbles tending to lie there-against. The presence of these gas bubbles against and adjacent the wheel results in non-uniform hardening of the same. Much of the cooling action is attained by the body of liquid in the tank 55 which is discharged through pipe 12 as it becomes heated, the coolant level being maintained by the liquid supplied through the orifices.

The operation of the apparatus just described is as follows: A wheel is mounted on the shaft I5 .been attained the wheel is lowered into the quench and sprayed through the orifices II, the wheel remaining until cooled to the desired temperature. Following this the shaft II is raised, the sleeve remaining the tank' until the wheel is above the tank, at which time the yoke 20 moves the sleeve under the wheel and the latter loaded on the sleeve by lowering the shaft. The yoke 22 is then withdrawn and a new wheel moved into position to be picked up by the shaft.

'It is Preferable to rotate the wheel during quenching, and sometimes during heating. This is accomplished by rotating the sleeve bearing against the wheel and to which it is drivingly connected by a key It. A gear 15 pinned to the sleeve is driven by an elongated spline II which in turn is power driven. The length of the spline permits rotation of the wheel in all positions if desired, as for instance with spaced heating brushes.

The supporting apparatus already described may be used in conjunction with modified forms oi heating rings and brushes. If it is desired to produce the contour of hardened surface shown in shaded lines in Fig. 2 rings II and 81 are provided, each shaped to conform to .the portion of the wheel contacted and cooled as described in conjunction with rings. II and I. A wheel to be hardened in this manner is provided with rings as shown and with acooling ring which is hollow and supplied with coolant to maintain the outer portion of the flange unhardened as indi- "cated. The cooling effect of the ring may be varied to control the portion of the flange main- 'tained below hardening temperature. With this modification the ring ll, as to position, correspondsto the ring II and the ring to the ring ll of Fig. 1. contacted by the lower brush system to permit passage of current between the rings II and II.

The modification shown in Fig; 4 is similar to the construction Just described in Fig. 2 except that a series of brushes l2 and II are spaced about .the portion of the wheel to be hardened. Current is passed through the wheel from one brush 82 to an adjacent brush N, thus providing a heated portion conforming to the contour shown in Fig. 4. Due to the distribution effect in the wheel and the close spacing of the brushes the heating is uniform.

In some cases 'it is desirable to heat only the rim portion of the wheel, and in this instance a brush system as shown in Fig. 3 is provided. This consists of a series of brushes I! spmed about the rim portion of the wheel and alternately connected to supply lines l1 and IS in such manner that current flows between alternate brushes and through the wheel. setting up a heated section as indicated in Fig. 3. In the modifications of both Figs. Ii and 4 cooling rings as ll are provided to maintain the unheated portion of the wheel below hardening temperature.

With each of the conductors shown in the various figures it is sometimes desirable to provide cooling rings I and I" (Fig. 2) to control the web temperature and eliminate spraying as used in thecooling ring ll shown in Fig. 1.

From the foregoing description it will be apapparent that I have. provided an electrical re- Ihe ring I1 is additional and is sistance heater mechanism to be used for heat treating the wear receiving portions of car wheels and that the same includes apparatus which is easy of loading and unloading and permits readily handling the wheels being treated.

Other forms may be employed embodying the features of my invention instead of the one herein explained, change being made as regards the means and the steps herein disclosed, provided the elements stated by any of the following claims or the equivalent of such stated elements be employed, whether produced by my preferred. method or by others embodying steps equivalent to those stated in the following claims.

I therefore particularly point out and distinctly claim as my invention:

1. In apparatus for hardening car wheels and the like, a frame, a current-conducting heating ring carried by said frame, a slideway in axial alignment with said ring carried by said frame, a support slidable on said slideway, a current-conducting ring parallel to said first-named ring carried by said support, each of said rings being adapted to engage the rim adjacent portions of a car wheel inter-posed therebetween, a support for a car wheel slidably carried within said flrstshaped form, a current-conducting heating element carried by one arm of said frame, a support slidably and rotatably carried by the other arm of said frame, a current-conducting element'carried by said support, said elements being adapted to engage the rim adjacent portions of a car wheel interposed therebetween, a support for a car wheel slidably carried by said first support, means to rotate said first-named support, and means to clamp said rings and a car wheel disposed therebetween in current conducting relation to pass heating current from one of said portions to the other.

3. In apparatus adapted to heat a car wheel by passing an electric current through the wearreceiving portion thereof, a frame, a pair of ringshaped resistance heating elements carried by said frame in axial alignment with each other, a support for a car wheel mounted on said frame for sliding movement along the same axis, means to move said support for engaging said two rings with the rim adjacent portions of a car wheel interposed therebetween, a quench tank mounted below the position of said current conducting relation of said rings and said wheel, said tank having an opening through the bottom thereof and means projecting through said opening to lower the bottom ring and the wheel into said quench tank to thereby cool the heated portion of said wheel.

4. In apparatus for heat treating car wheels and like articles, means to raise a predetermined portion of said article to an elevated temperature, a quench tank to receive said portion below the coolant level in said tank, said tank having an opening at the bottom thereof and means projecting through said opening for lowering said portion below said level.

FRANCIS S. DENNEEN. 

